Echo distance measuring systems



Feb. 2l, 1961 J. N. BEEEsE.` 2,972,731

ECHO DISTANCE MEASURING SYSTEMS Original Filed Oct. 16, 1948 2Sheets-Sheet 1 faremmo @Nm/VG l fanwarea sraksoako P01? 7' M' TWORK lTRM/saws@ TRM/500654 Arm/1WD Feb. 2l, 1961 J.` N. BEEBE ECHOy DISTANCEMEASURING SYSTEMS Original Filed Oct. 16, 1948 2 Sheets-Sheet 2 o I/ oNG L6 III? AJM/f l :of: auf I l I I I I I I l I I I I l I I I I I I I II I [1f/h5 I 'E J CLL/L2( ECHO DISTANCE MEASURING SYSTEMS John N. Beebe,Newton, Mass., assignor to Raytheon "Company, a corporation of DelawareContinuation of application Ser. No. 54,851, Uct. 16, 1948. Thisapplication Sept. 13, 1949, Ser. No. 115,342

17 Claims. (Cl. 340-3) This is a continuation of my copendingapplication, Serial No. 54,851, led'October 16, 1948 (now abandoned).

The present invention relates to echo sounding systems fornavigablevessels, and is particularly designed for use aboard barge towsof the kind used on the inland waterways.

The main object of this invention is to provide a versatile echosounding system which will furnish information about the depth of waterbeneath any one of a number of chosen points on a navigable vessel.

It is another object to provide such a system which will selectivelyfurnish a depth indication from any chosen one of such points.

It is a particular object of the invention to provide an echo soundingsystem which will furnish information about the depth of water beneatheither side, port or starboard, forward on the bow, or aft at the sternof complex barge tow.

It is a further object of the invention to provide such a system whichis portable to the-extent required for versatility of installationaboard barge tows which change in composition from one port of call tothe other, at a minimum cost consistent with a high qualityinstallation.

The present invention accomplishes the foregoing and other objects byproviding separate transducers fore and aft, and on the port andstarboard sides, on a vessel together with novel means for selectivelyenergizing certain ones of them from echo sounding in chosen regions.The selection is accomplished with the aid of a frequency selectivecircuit to which signals of one or the other of two frequencies can beapplied and which in turn provides a particular frequency to each of twotransducers which are connected thereto. The invention further employsthe frequency which is not applied to the selective circuit to energizestill another transducer, so that soundings in two selected locationsmay be simultaneously had.

The foregoing and other objects of the invention will become moreapparent from the following description of certain embodiments thereof,reference being had to the accompanying drawing wherein:

Fig. l diagrammatically illustrates a typical barge tow with the systemof the present invention installed aboard;

Fig. 2 is an electrical schematic partly in block diagram form of theembodiment of the invention shown in one condition of operation;

Fig. 3 illustrates a second condition of operation of the embodiment ofFig. 2;

Fig. 4 is an electrical schematic of the dividing network of Fig. 2;

Fig. 5 illustrates a second embodiment of the invention; and

Fig. 6 illustrates a third embodiment of the invention.

Referring now to Fig. 1, a powered vessel 10 is shown .pushing andpulling a group of barges 11. The barges 11 are fastened together one infront of the other at the bow end of the tow unit 10 until a substantiallength, for example 1,000 feet, is reached. Additional b arges 2,972,731Patented Feb. 21, 1961 11 are then often fastened to the tow at thesides thereof. The navigator of the entire tow, who is stationed in thepilot house 12 of the tow unit 10, is faced constantly with the problemof knowing the depth of water beneath the tow. The information mostneeded is information about the depth of water at the forward end 13 ofthe tow, particularly at the port and starboard sides. It isadvantageous also to have information about the depth of water at theaft end on both sides.

The system of the present invention contemplates the installation ofecho sounding transducers 14, 15, 16 and 17 at the bow and stern of thebarge tow, on the port and starboard sides thereof, so that depthinformation from these four most important points will be constantlyavailable-to the navigator. Because inland waterways, such as forexample the Mississippi and Ohio Rivers, are rarely free of floatingobjects such as logs, it is preferred to place the forward transducers14 and 15 of the system of the present invention just off the bow at theport and starboard sides, respectively. The water stream at these pointsusually carries floating objects away from the tow without injuring thetransducers. Twoadditional transducers 16 and 17 are desirably installedaft at the port and starboard sides, respectively.

Electronic equipment of a kind to be described more particularly belowis installed in the pilot house 12 for transmitting and receivingsignals to and from selected ones of the transducers 14 to 17,inclusive. To carry these signals, signal connections 20 and 21 areprovided from the aft transducers 16 and 17, respectively, to the pilothouse 12, and a single cable 22 provides the signal connection to bothforward transducers 14 and 15. By this feature, the present inventioneliminates the cost of a long cable and its connecting devices.Cooperating with the cable 22 is a frequency dividing network 23 locatedforward and connected by signal connections 24 and 2S with the forwardtransducers 14 and 15, respectively. At each barge of the tow acrosswhich a signal connection 20, 21, 24 or 25 passes, there is located inthe connection a two-piece ca-ble connector 26 of a kind to be discussedmore fully below. As will be appreciated from the `description tofollow, this system provides soundings of the depth of water at the mostimportant points of the barge tow and enables continued navigation underthe most adverse weather conditions.

Referring now to Fig. 2, a 40 kc. transmit-receive circuit 30 and a 50kc. transmit-receive circuit 31 are located in the pilot house 12. Astheir names imply, the 40 kc. transmit-receive circuit is an electroniccircuit which generates a pulse of 40 kc. energy to be furnished to aselected transducer, and at the same time generates a timing wave and isadapted, upon being provided with an echo of said pulse, to furnish avoltage which is measurably related to the time elapsing between thegeneration of the pulse and the reception of the echo. The 50 kc.circuit functions in the same manner but operates at a frequency of 50kc. Circuits for accomplishing this function are known, and hence arenot illustrated herein. As an example of a suitable circuit I prefer touse, I refer to the disclosure of pending application, Serial No.749,426, tiled May 21, 1947, now Patent No.

2,502,938, dated April 4, 1950.

Located also in the pilot house 12 is a yfour-bank control switch 32shown surrounded by a dotted line box 65. The first bank 33 has a rstmain contact 34 and l two selection contacts 35 and 36, respectively. Arotatwhich is dimensioned to make Contact with the main contact 41 andone or the other of the selection contacts 42 and 43. The second bank 38Ahas also a second main contact'46'and third and fourth selectioncontacts -47 and 48, respectively, cooperating with a second rotatableelement 49 which is dimensioned to make contact with the second maincontact 46 and one or the other of the third and fourth selectioncontacts 47 and 48. The first Vandrsecond banks 33 and 38 of the switch32 are ganged together so that in one position, rotatable yelement 37 isin contact with its rnain contact 34 and selection contact 36, at thesame time that rotatable element 44 is in contact with its main contact41 and selection contact 43 and rotatable element 49, yis in contactwith its main contact 46 and selection contact 47.

The 40 kc. transmit-receive circuit 30 is connected at its vpulse outputand input terminals 51 to the first main contact 41 of bank 38. The 5'0kc. transmit-receive circuit 31 is connected at its pulse output andinput terminals 52 to the main contact 34 of bank 33. The aft starboardtransducer 17 is connected by the `signal cable 21 to the rst selectioncontact 42 of bank 38. The aft .port transducer 16 is connected by thesignalkcable 20 to the second selection contact 36 of bank 33. The iirstselection contact 35 of bank 33 is directly connected by way of a wire53 to the fourth selection contact 48 of bank 38. The third selectioncontact 47 of bank 38 .is connected by a wire 54 to the second Selectioncontact 43 of the same bank. The second main vcontact 46 of bank 38 isconnected to the cable 22 which leads forward to the dividing network 23and thence to the forward transducers 14 and 15.

With the switch 32 in the position shown, a circuit can be traced fromthe 40 kc. transmit-receive circuit 30 through the first main contact41, and second and third selection contacts 43 and 47 and the secondmain contact 46 of bank 38 to the cable 22 leading forward. Thisprovides the 40 kc. signal to the dividing network 23. As will beexplained in detail below, the dividing network passes the 40 kc. signalto the forward port transducer 14, and no 40 kc. signal is passed to thestarboard transducer 15. At the same time, a circuit can be traced fromthe 50 kc. transmit-receive circuit 31 via the first main contact 34,and second selection contact 36 of the iirst bank 33 to the aftl porttransducer 16. Thus with Vthe switch 32 in the position shownthe forwardport transducerr14 is operated with 40 kc. energy, and the aft porttransducer 16 is operated with 50 kc. energy.

Referring now to Fig. 3, the switch 32 is shown in a second positionwhich is arrived at by rotating the ganged o main contact 41 with thefirst selection contact 42, while lthe second rotatable element 49 ofbank 38 now .connects the second main contact 46 with thefourthselection contact 48. A circuit can now be'traced from the pulseterminals 51 0f the 40 kc. circuit 30 through the first vmain contact 41and first selection contact 42 of `bank 38 to cable 21, and thence tothe aft starboard transducer 17. A second circuit can now be traced fromthe pulse terminals 52 of the 50 kc. circuit 31 through the main contact34 and rst selection contact 35 of bank-33 to the fourth selectionContact 48 of bank 38 via wire 53, and then to the second maincontact'46 of bank 38 to cable 22 which carries the 50'kc. signalAforward to the dividing network 23. The dividing network 23, as will beexplained below, passes the 50 kc. signal tothe starboard transducer 15,and no 50 kcsignal is passed to the port transducer 14. The 40 kc.signal is provided to the aft starboard transducer 17. Thus with theswitch 32 in its second position, soundings are made on the starboardside of the tow. It will lbe convenient to refer to the first positionof switch 32 as the port position and the second position thereof as thestarboard position.

A means of indicating the position of the switch 32 in a darkened pilothouse may be provided employing a second rotatable member 56 of thefirst bank 33 and its cooperating main and first and second selectioncontacts 57, 58 and 59, respectively. A battery 61 is connected at oneterminal to the main contact 57. Atirst lamp 62 vis connected vat oneside to the rst vselection contact 58.

A second lamp 63 is connected at one side to the second selectioncontact 59. The remaining sides of the lamps are connected together tothe remaining side of the battery 61. As can be seen from Figs. 2 and 3,the tirst lamp 62 is connected in circuit with the battery 61 rwhen theswitch 32 is in the port position, and the second lamp 63 is connectedin circuit with the battery 61 when the switch 32 is in the starboardposition, the iirst lamp 62 then being disconnected. The lamps 62 and 63are conveniently labelled port and starboard pilot lights.

The cables 20, 21, 22, 24 and 25 are two-conductor cables. However,within the casing 65 of the switch 32 a shielded single conductor isconnected to the appropriate contact of the switch. The casing 65, whichis electrically conductive, isV grounded as at 66, and one conductor ofeach signal cable is electrically connected thereto.

The coupling units 26 are each a Vtwo-piece transformer of which theprimary and secondary windings `are physically separable. The electricalnature of these coupling units is schematically illustrated in the unitconnected in cable 22. The primary winding 68 is connected to the pilothouse end of the cable 22. Together with an iron core 69, this windingis contained in one half 70 of the coupling unit. The other half 71 ofthe coupling unit contains a secondary winding 72 and in seriestherewith a condenser 73 which is intended to tune out at least part ofthe leakage reactance of the coupling unit. The second half 71 of thecoupling unit is connected to the dividing network side of the cable 22.I prefer to employ coupling units of having the physical structure shownand `described in my co-pendingapplication, Serial No. 13,3"12, filedMarch 5, 1948. These coupling units are physically strong and readilyseparable without the generation of sparks and hence safe to use aboardbarges carrying inflammable materials.

Each of the transmit-receive circuits 36 and 31 is provided with a meansfor indicating the depth being measured. In the present embodiment, theindicators are of the meter type, and two separate meters '75 and 76 areprovided, each of which can be operatedselectively from one or the otherof the transmit-receive circuits, in accordance with the setting, portor starboard, of the control switch 32. The first meter 75 indicatesdepth forward and is so labelled, while the second meter 76 indicatesdepth aft and is Vlikewise Vso labelled. When'the control switch 32 isin the port position, the forward meter 75 is connected to the outputtermin-als 77 and 78 of the 40 kc. transmit-receive circuit 30 through athird bank 81 of the control switch 32. Simultaneously, the second oraft meter 76 is connected to the output terminals 83 and S4 of the 50kc. transmit-receive circuit 31 through a fourth bank 82 of the controlswitch 32. The third and fourth banks 81 and 82 are ganged with thefirst and second banks 31 and 38 of the control switch 32. A singledashed line 85`linking all four banks indicates this ganging. The metercircuit of the forward meter can be traced from the positive terminal 77of the 40 kc. transmit-receive circuit 30 to a first 'main contact 87 ofthe third bank 81, then through the rotatable element 88 and firstselection contact 89 thereof, then through the forward meter y75 to thethird selection contact 91 of the third bank S1, then through the secondrotatable element 92 and second main contact'93 thereof to the negativeterminal 78 of said Vtransmit-receive circuit. A'similar circuit can betraced for the aft meter,

starting with the positive output terminal 84 of the 50 kc.transmit-receive circuit 31. This meter circuit is traced to the rstmain contact 97 of the fourth bank 82, then through the iirst rotatableelement 98 and first selection contact 99 thereof to the positiveterminal of the aft meter 76, from the negative terminal of the aftmeter 76 to the third selection contact 101, second rotatable contact102 and second main contact 103 of the fourth bank 82, and thence to thenegative output terminal 83 of said 50 kc. circuit. There are providedthe following direct connections from the third bank S1 to the fourthbank 82:

A connection 105 from rst selection contact 89 to second selectioncontact 104;

A connection 107 from second selection contact 94 to first selectioncontact 99;

A connection 108 from third selection contact 91 to fourth selectioncontact 106; and

A connection 109 from fourth selection contact 96 to output terminal 77of the 40 kc. transmit-receive circuit 30 to the first main contact 37of the third bank 81, then through the rst rotatable member 88 andsecond selection contact 94 thereof to the positive terminal of themeter 76, then from the negative terminal of said meter through directconnectionV 109 to the fourth selection Contact 96 of the third bank S1,then through the second rotatable member 92 and second main contact 93thereof to the negative terminal 78 of said 40 kc. circuit. Similarlythe circuit of the forward meter 75 can be traced from the positiveterminal 84 of the 50 kc. transmit-receive circuit 31 to the first maincontact 97 of the fourth bank 82, then through the first rotatablemember 98 and second selection contact 104 thereof to the positiveterminal of the meter 75, then from the negative terminal of said meterto the fourth selection contact 106 of the fourth bank 82, then throughsecond rotatable member 102 and the second main contact 103 thereof tothe negative terminal 83 of said 50 kc. transmit-receive circuit.

Thus it can be seen that when the control switch 32 is in the portposition, the 40 kc. transmit-receive circuit furnishes energy forward,and the forward meter 75 is Simultaneously connected thereto, While the50 kc. transmit-receive circuit furnishes energy aft, and the aft meter76 is simultaneously connected thereto; andwhen the control switch 32 isin the starboard position, the 50 kc. transmit-receive circuit furnishesenergy forward, andthe forward meter 75 is connected thereto, whilesimultaneously the 40 kc. transmit-receive circuit furnishes energy aftand the aft meter 76 is connected thereto. With this system therefore,the navigator is able to choose soundings from either side, port orstarboard, and will obtain information about the depth both forward andaft on the chosen side.

Indicator lights 111 and 112 may be provided if desired for the forwardand aft meters 75 and 76, respectively. When these lights are provided,a suitable source of power, such as a battery 113, is necessary, and adimming control, for example a rheostat 114 in series therewith, isdesirable.

Referring to Fig. 4, the circuit of the dividing network 23 is thereillustrated. The single cable 22 running between the `pilot house 12 andthe dividing network is brought in at the bottom of the figure where oneconductor is grounded at 116 and the second conductor is connected at aterminal 117 to two parallel branches 118 and 119 of the circuit. Therst parallel branch 11S has in series a capacitor 121, a parallelresonance circuit 122 consisting of an inductor 123, and a secondcapacitor ,124 connected in parallel with respect to each other,

a second inductor 125 and a third capacitor 126. The second branch 119ofthe network circuit has in series an inductor 131, a parallelresonance circuit 132 having a second inductor 133 and a capacitor 134connected in parallel with respect to each other, a third inductor 135and a second capacitor 136. The two parallel branches 118 and 119 arebrought together at the upper ends to a terminal 137 which is groundedas at 138. The 40 kc. output, which is provided to the signal connection24 to the port transducer 14, istaken across the second inductor 125 andthird capacitor 126 of the iirst branch 118. The 50 kc. output, which isprovided to the signal connection 25 to the starboard transducer 15, istaken across the third inductor 135 and second capacitor 136 of thesecond branch 119.

The circuit of the dividing network 23 functions in the manner of a bandrejection filter. In the first branch 118, the parallel resonancecircuit 122 is resonant to 50 kc. per second and hence introducessubstantially iniinite impedance in this branch to 50 kc. signals whilepermitting 40 kc. signals to pass. On the other hand, the seriesarrangement of the second inductor 125 and third capacitor 126 of thefirst branch 118 is not resonant to 40 kc. per second, so that asubstantial voltage can be developed thereacross for the 40 kc. signal.In a similar fashion, the parallel resonance circuit 132 of the secondbranch 119 is resonant to 40 kc. per second while the series arrangementincluding the third inductor 135 and the second capacitor 136 of thisbranch is not resonant to 50 kc. per second. Thus in the second branch119 there is substantially infinite impedance to 40 kc. signals, while50 kc. signals are passed and develop a signal voltage in the thirdinductor 135 and second capacitor 136.

Suitable values for the various circuit elements shown in Fig. 4 are asfollows:

When the control station 32 is not only a substantial distance from theforward transducers 14 and 15, but also a substantial distance from theaft transducers 16 and 17, the arrangement shown in Fig. 5 may be em,-ployed to advantage. In this arrangement, the second selection terminal36 of the first switch bank 33 and the first selection terminal 42 ofthe second switch bank 38 are connected together, for example to acommon terminal 141. A single cable 142 runs aft from this commonterminal to a second dividing network 143 which is similar in all mainrespects to the forward dividing network 23. Magnetic connectors 26 areincluded in this cable as suitable. The signal connections 20 and 21 ofthe port and starboard aft transducers 16 and 17, respectively, arebrought into the aft dividing network V143. Recalling that the forwarddividing network 23 sends 40 kc. signals to the port side and 50 kc.signals to the starboard side, it will be appreciated that the aftdividing network 143 should be arranged to send 50 kc. signals to theport side and 40 kc. signals to the starboard side.

In some installations it may be desired to employ only one afttransducer, for example there may be no barges 11 secured to thetow unit10 itself. In such installations, as shown in Fig. 6, the aft dividingnetwork 143 and the port and starboard aft transducers are omitted,

g and a single transducer 145 is connected to the common terminal 141 byway of a suitable length of cable 142.

Since other modifications of vtheinvention, not lherein illustrated,will 'occur to those Skilled in the art, it is intended that the claimsthat 'follow shall not be limited by the 'details of the variousembodiments described vherein but only by the prior art.

What is claimed is:

1. An echo sounding system comprising first transmit ting and receivingmeans adapted for operation at afirst frequency, secondtransmitting andreceiving means adapted for operation at a second frequency, first andsecond electroacoustic transducers disposed in first and secondlocations where soundings are to be taken, remote Afromsaid'transmitting and receiving means, switch means having a main and'first 'and second selection contacts on either one of which said maincontact can be 'selectively closed, a dividing network having threeterminal means of which the first is substantiall-y impassable to saidfirst frequency, the second isY substantially impassable to said secondfrequency, and the third passes both of said frequencies, meansconnecting said first transmitting and receiving means to said firstselection contact, means connecting said second transmitting andreceiving means to said second selection contact, means connecting saidmain contact to said third terminal means, means connecting said firsttransducer to said first terminal means, and means connecting saidsecond transducer to said second terminal means.

2. An echo sounding system comprising first transmitting and receivingmeans adapted for operation at a first frequency, second transmittingand receiving means adapted for operation at a second frequency, firstand second electroacoustic transducers disposed in first and ytransmitting and receiving means to said first selection contact, meansconnecting said second transmitting and receiving means to said secondselection contact, 'means connecting said main contact to saidthirdterminal means, means connecting said first transducer to said firstterminal means, means connecting .said second transducer to 'said'secondterminal means, depth indicating means, and

means for selectively connecting said indicating means to the one ofsaid transmitting and receivingmeans that is connected to said thirdterminal means through said switch means.

3. An echo sounding systeml comprising first Vtransmitting and receivingmeans adapted for operation at a first frequency, second transmittingand receiving means adapted for operation at a second frequency, firstand second electroacoustic transducers disposed in Ifirst and secondlocations where soundings are to be taken, remote from said transmittingand receiving means, first switch means having first main and Jfirst andsecond selection contacts on either one of which said first main contactcan be selectively closed, a dividing network having three terminalmeans of which the first is substantially impassable to said firstfrequency, the second is substantially impassable to said secondfrequency, and the third passes both of said frequencies, meansconnecting said main Contact to said third terminal means, meansconnecting said first transducer to said first terminal means, meansconnecting said Second transducer to said second terminal means, secondswitch means having second main and third and fourth selection contactson either one of which said second main contact can be selectivelyclosed, means connecting said first transmitting and receiving means tosaid second main contact, "means connecting said first and thirdselectioncon- '8 tacts together, third switch means 'having third main`and fifth and sixth selection contacts on either one of which saidthird main contact can be selectively closed, means connecting Vsaidsecond transmitting and receiving means to said third main contact,means connecting said second and sixthselection contacts together, andvadditional transducer means connected to said fourth and fifth'selection contacts.

4. An echo sounding system comprising first transmitting and receivingmeans adapted for operation at a first frequency, second transmittingand receiving means adapted for operation at a second frequency, firstand second electroacoustic transducers disposed in first and Secondlocations where soundings are to be taken, remote from said transmittingand receiving means, first switch means having first main and first andsecond selection contacts on either one of which said first main contactcan be selectively closed, a dividing network having three terminalmeans of which the first is substantially impassable to said firstfrequency, the second is substantially/impassable to said secondfrequency, and the third passes both of said frequencies, meansconnecting said main contact to said third terminal means, meansconnecting said first transducer to said first terminal means, meansconnecting said second transducer to said second terminal means, secondswitch means having second main and third and fourth selection contactson either one of which said second main contact can be selectivelyclosed, means connecting said first transmitting and receiving means tosaid second main contact, means connecting said first and thirdselection contacts together, third swich means having third main andfifth and sixth selection Vcontacts on either one of which said thirdmain contact can be'selectively closed, means connecting said secondtransmitting and receiving means to said third main contact, meansconnecting said second and sixth selection contacts together, -andadditional transducer means connected to said fourth and fifth selectioncontacts, said first, second, and third switch means being gangedtogether so that in one operative position said first, second, and thirdmain contacts are closed on said first, third and fth selectioncontacts, respectively, and in another operative position on saidsecond, fourth, and sixth selection contacts, respectively. Y 5. AnAecho sounding system comprising first transmitting and receiving meansadapted for operation at a first frequency, second transmitting andreceiving means adapted for operation at a second frequency, first andsecond electroacoustic transducers disposed in first and secondlocations where soundings are to be taken, remote from said transmittingand receiving means, first switch means having first `main and first andsecond selection contacts on either one of which said first main contactcan be selectively closed, a dividing network having three terminalmeans of which the first is substantially impassable to said firstfrequency, the second is 'substantially impassable to said secondfrequency, and the third passes both of said frequencies, meansconnecting said main contact to said third terminal means, meansconnecting said first transducer to said first terminal means, meansconnecting said second transducer to said second terminal means, secondswitch means having second main and third and fourth selection contactson either one of which said second main contact can be selectivelyclosed, means connecting said first transmitting and receiving means tosaid second main contact, means connecting said first and thirdselection contacts together, third switch means having third main andfifth and sixth selection contacts on either one of which said thirdmain contact can be selectively closed, means connecting said secondtransmitting and receiving means to said third main contact, meansconnecting said second and sixth selection contacts together, a thirdelectroacoustic transducerfdisposed in a third location where soundingsare to be taken, and means vconnecting said third transducer to saidfourth and fifth selection contacts in common.

6. An echo sounding system comprising first transmitting and receivingmeans adapted for operation at a first frequency, second transmittingand receiving means adapted for operation at a second frequency, firstand second electroacoustic transducers disposed in first and secondlocations where soundings are to be taken, remote from said transmittingand receiving means, first switch means having first main and first andsecond selection cont-acts on either one of which said first maincontact can be selectively closed, a dividing network having threeterminal means of which the first is substantially impassable to saidfirst frequency, the second is substantially impassable to said secondfrequency, and the third passes both of said frequencies, meansconnecting said main contact to said third terminal means, meansconnecting said first transducer to said first terminal means, meansconnecting said second transducer to said second terminal means, secondswitch means having second main and third and fourth selection contactson either one of which said second main contact can be selectivelyclosed, means connecting said first transmitting and receiving means tosaid second main contact, means connecting said first and thirdselection contacts together, third switch means having third main andfifth and sixth selection contacts on either one of which said thirdmain contact can be selectively closed, means connecting said secondtransmitting and receiving means to said third main contact, meansconnecting said second and sixth selection contacts together, third andfourth electroacoustic transducers disposed in third and fourthlocations where soundings are to be taken, a second dividing networkhaving fourth, fifth, and sixth terminal means of which said fourthterminal means is substantially impassable to said first frequency, saidfifth is substantially impassible to said second frequency, and saidsixth passes both of said frequencies, means connecting said fourth andfifth contacts in common to said sixth terminal means, means connectingsaid third transducer to said fourth terminal means, and meansconnecting said fourth transducer to said fifth terminal means.

7. An echo sounding system comprising first transmitting and receivingmeans adapted for operation at a first frequency, second transmittingand receiving means adapted for operation at a second frequency, firstand second electroacoustic transducers disposed in first and secondlocations where soundings are to be taken, remote from said transmittingand receiving means, first switch means having first main and first andsecond selection contacts on either one of which said first main contactcan be selectively closed, a dividing network having three terminalmeans of which the first is substantially impassable to said firstfrequency, the second is substantially impassable to said secondfrequency, and the third passes both of said frequencies, meansconnecting said main contact to said third terminal means, meansconnecting said first transducer to said first terminal means, meansconnecting said second transducer to said second terminal means, thirdand fourth electroacoustic transducers disposed in third and fourthlocations where soundings are to be taken, second switch means havingsecond main and third and fourth selection contacts on either one ofwhich said second main contact can be selectively closed, meansconnecting said first transmitting and receiving means to said secondmain contact, means connecting said first and third selection contactstogether, means connecting said third transducer to said fourthselection contact, third switch means having third main and fifth andsixth selection contacts on either one of which said third main contactcan be selectively closed, means connecting said second transmitting andreceiving means to said third main contact, means connecting said secondand sixth selection contacts together,

. t Y. i@ and means connecting said fourth transducer to said fifthselection contact.

8. An echo sounding system for use aboard navigable vessels comprising aport-side electroacoustic transducer, a starboardside electroacoustictransducer, first transmitting and receiving means adapted for operationat a first frequency, second transmitting and receiving means adaptedfor operation at a second frequency, a control station located aconsiderable distance from said transducers, a frequency selectivedividing network located near said transducers, a single signal cableconnected between said station and said network, separate signalconnections between said network and each of said transducers, signalconnections between each of said transmitting and receiving means andsaid station, and switch means at said station for selectivelyconnecting one or the other of said transmitting and receiving means tosaid single cable, saidY network being dimensioned to pass said firstfrequency to one of said transducers and said second frequency to theother of said transducers.

9. An echo sounding system for use aboard a navigable vessel comprisinga port-side electroacoustic transducer, a starboard-side electroacoustictransducer, both located forward on said vessel, first transmitting andreceiving means adapted for operation at a first frequency, secondtransmitting and receiving means adapted for operation at a secondfrequency, a control station located a considerable distance from saidtransducers, a frequency selective dividing network located near saidtransducers, a single signal cable connected between said station andsaid network, separate signal connections between said network and eachof said transducers, signal connections between each of saidtransmitting and receiving means and said station, aft-locatedelectroacoustic transducer means, signal connection means between saidafter transducer means and said station and switch means having twooperative positions for port and starboard forward soundingrespectively, said switch means being adapted when in said port positionto connect said first transmitting and receiving means to said cable andsaid second transmitting and receiving means to said signal connectionmeans, and when in said starboard position to reverse said connections,said network being dimensioned to pass said first frequency to one ofsaid forward transducers and said second frequency to the other of saidforward transducers.

10. Anecho sounding system for use aboard a naviable vessel comprising aport-side electroacoustic transducer, a starboard-side electroacoustictransducer, both located forward on said vessel, first transmitting andreceiving means adapted for operation at a first frequency, secondtransmitting and receiving means adapted for operation at a secondfrequency, a control station located a consider-able distance from saidtransducers, a frequency selective dividing network located near saidtransducers, a single signal cable connected between said station andsaid network, separate signal connections between said network and eachof said transducers, signal connection between each of said transmittingand receiving means and said station, aft-located electroacoustictransducer means, signal connection means between said after transducermeans and said station and switch means having two operative positionsfor port and starboard forward sounding respectively, said switch meansbeing adapted when in said port position to connect said firsttransmitting and receiving means to said cable and said secondtransmitting and receiving means to said signal connection means, andwhen in said starboard position to reverse said connections, saidnetwork being dimensioned to pass said first frequency to one of saidforward transducers and said second frequency to the other of saidforward transducers, first and second depth indicating means, forforward and aft depth indications, respectively, furtherl switch meansat said station adapted to connect said rst indicating means to theoutput of the.

transmitting and receiving means which is connected to said cable andsaid second indicating means to the output ofthe other transmitting andreceiving means.

l1. An echo sounding system for use aboard, a navigable vesselcomprising a port-side electroacoustic transducer, a starboard-sideelectroacoustic transducer, both located forward on said vessel, iirsttransmitting and receiving means adapted for operation at a firstfrequency, second transmitting and receiving means adapted for operationat a second frequency, a control station located a considerable distancefrom said transducers, arfrequency selective dividing network locatednear said transducers, a single signal cable connected between saidstation and said network, separate signal connections between saidnetwork and each of said transducers, signal connections between each of.said transmitting and receiving means and said station, aft-locatedelectroacoustic transducer means, signal connection means between saidafter transducer means and said station and switch means having twooperative positions for port and starboard forward soundingrespectively, said switch means being adapted when in said port positionto connect said first transmitting and receiving means to said cable andsaid second transmitting and receiving means to said signal connectionmeans, and when in said starboard position to reverse said connections,said network being dimensioned to pass said first frequency to one ofsaid forward transducers and said second frequency to the other of saidforward transducers, first and second depth indicating means, forforward and aft depth indications, respectively, further switch means atsaid station adapted to connect said iirst indicating means to theoutput of the transmitting and receiving means which is connected tosaid cable and said second indicating means to the output. of the othertransmitting and receiving means, said switch means being all ganged forcommon operation from a single control.

l2. An echo sounding system for use aboard a navigable vessel comprisingfirst, second, third, and fourth electroacoustic transducers locatedrespectively forward on the port and starboard sides and aft on the portand starboard sides, first and second transmitting and receiving meansadapted for operation at first and second frequencies, respectively, acontrol station located a considerable distance from said first andsecond transducers, a frequency selective dividing network locatedforward near said first and second transducers, a single signal cableconnected between said station and said dividing network, firstV andsecond signal connections between said network and said first and secondtransducers, respectively, third and fourth signal connections betweensaid station and said third and fourth transducers, respectively, andswitch means at said station having two operative positions for port andstarboard sounding, respectively, said switch means being adapted whenin said port position to connect said irst transmitting and receivingVmeans to said cable and said second transmitting andv receiving meansto said third transducer, and when in saidstarboard position to connectsaid second transmitting and receiving means to said cable and saidfirst transmittingV means to said fourth transducer, said dividingnetwork being dimensioned to pass said first frequency to the porttransducer and said second frequency to the starboard transducer. Y

i3. An echo sounding system forV use aboard a navigable Vesselcomprising first, second, third, and fourth electroacoustic transducerslocated respectively forward on the port and starboard sides and aft orithe port and starboard sides, first and second transmitting andreceiving means adapted for operation at first and second frequencies,respectively, a controlstation located a considerable distance from saidtransducers, a first frequency selective dividing network locatedforward near said first and second transducers, first and second signalconriectioris between said first network and said first and secondtransducers, respectively, a first signal cable between said firstnetwork and said control station, a second frequency selective-dividingnetworkrlocated aft near said thirdY and fourth transducers,` third andfourth signal connections between said secondV network and s aidthirdand fourth transducers, respectively, a second signal cable betweensaidrrsecond network andsaid control station, and switch meansV at saidstation having two operative positions for port and starboard sounding,respectively, said switch means being adapted when in said port positionto connect said rst and second transmitting and receiving means to saidfirst and second cable, respectively, and when lin said starboardposition to reverse said connections, said lirst dividing network beingdimensioned to pass said rst frequency to said first transducer andVsaid second frequency to said second transducer, and said seconddividing network being dimensioned to pass said second frequency to saidthird transducer and Vsaid first frequency to said fourth transducer.

14, A signal transmitting-'ind-receiving system comprising rst andsecond signaling transducers located respectively in first` and secondseparate regions, first and second separate transmitting and receivingmeans adapted for operation. at first and second frequencies,respectively, a frequency dividing network, switch means conneetedybetween said transmitting and receiving means and said network andarranged selectively to provide a signaly of one or the other of saidtransmitting-andreceiving means to said network, and separate signalconnections between said network and each of said transducers, saidnetwork being dimensioned to pass said first frequencyto one of saidtransducers and said second frequency to theother of said transducers.

l5. A signal transmitting-and-receiving system ernpioying twoA separatesignaling transducers located respectively. in first ,andV secondseparate regions for distance finding in different regions, means for`choosing one or the other of said transducers comprising first andsecond separate transmitting-and-receving means providing transducerenergizing signals of two different frequencies, a

frequency dividing network, means selectively connecting a signal ofrone or the other of said transmitting-andreeeiving meansV to saidnetwork, and separate signal connections from said network to eachtransducer, said network being dimensioned to pass one of saidfrequencies to one of said connections and the other frequency to theother connection. t

i6. A signal. transmitting-andreceiving system comprising first andsecondv signaling transducers located respectively in first and secondseparate regions, first and second separate., transmitting-and-receivingcircuits remotely located with respect to said transducers and adapted-to provide energizing signals for said transducers at first and secondfrequencies, respectively, a frequency dividing network located nearsaid transducers and having input terminalmeans arranged to accept saidsignals, first output terminal means which passes said iii-st but notsaid second frequency and second output terminal, means which passessaid second but not said first frequency, a single signal transmissionmeans arranged tok bring said signals to said input terminal means, ayswitch in said single transmission means arranged to connect oneV orthe other of said transmitting-and-receivirig circuits thereto, meansconnecting said iirst transducer to said first output terminal means,and means connecting said second transducer to said second outputterminal means,

t 17. A signal transmitting-and-receiving system comprising first andsecond signaling transducers located respectively in first and secondseparate regions, first and second separate t1'ansmittirig-and-receivingcircuits adapted to provide energizing sigualsfor said transducers atfirst and second frequencies, respectively, signal switching meanshaving a first inputconnected to said first 13transmitting-and-receiving circuit to accept signals of said rstfrequency, a second input connected to said secondtransmitting-and-receiving circuit to accept signals of said secondfrequency, and a signal output to which one or othe other of saidfrequencies is provided, a frequency dividing network having inputterminal means arranged to accept said signals, rst output terminalmeans which passes said first but not said second frequency and secondoutput terminal means which passes said second but not said rstfrequency, means connecting said rst transducer to said first outputterminal means, means connecting said second transducer to said secondoutput terminal means, and means connecting said signal output to saidinput terminal means.

References Cited in the le of this patent UNITED STATES PATENTS

